The Federal Emergency Management Administration establishes "base flood" levels for regions susceptible to flooding. FEMA estimates base flood as the level at which flooding has a 1 percent chance of occurring each year. You may know this as the 100-year flood level, or the level a flood reaches only once every hundred years. Only properties with a 1 percent chance or higher of flood each year are at base flood elevations. Learn how to read a flood insurance rate map and determine your property's base flood elevation.
Go to FEMA's website (fema.gov) and click "Disaster & Maps" at the top of the page.
Click "Maps" at the top-left of the screen, then select "Flood Maps" toward the top of the screen.
Select "Flood Insurance Rate Maps," then "Find a FIRM."
Enter a property's address at the top-left of the screen, then click "Search by Street Address."
Select "View" in the results screen. The map usually takes a few minutes to load.
Click on the map in the vicinity of your property to zoom in. Your property has a base flood elevation if it is in an area shaded green.
Note the letters that indicate the zone where your property lies, then read the legend on the right side of your flood map to find your base flood elevation.